Method and apparatus for delivering an agent to the abdomen

ABSTRACT

A method and apparatus for treating gas for delivery into a body cavity, body space or body surface of an animal. The apparatus comprises a housing defining a chamber having an entry port and an exit port. One or more agents are released into the gas stream that flows through the chamber so that the gas stream carries the agent to the animal. Also shown, for use with, or without, the chamber, is an agent chamber adapted to be coupled to at least one structure defining at least one fluid flow path extending at least a portion of the distance between an insufflation device and the body cavity, body space or body surface.

RELATED APPLICATIONS

This application is a continuation-in-part of U.S. application Ser. No.09/363,234, filed Jul. 27, 1999 now U.S. Pat. No. 7,250,035, entitled“Method and Apparatus for Treating Gas for Delivery to an Animal”, whichis a continuation-in-part of U.S. application Ser. No. 09/081,186, filedMay 19, 1998 now U.S. Pat. No. 6,068,609, entitled “Method and Apparatusfor Conditioning Gas for Medical Procedures Having Humidity Monitoringand Recharge Alert”, and of U.S. application Ser. No. 09/314,052, filedMay 18, 1999, entitled “Method and Apparatus for Conditioning Gas forMedical Procedures”, which is also a continuation-in-part of U.S.application Ser. No. 09/081,186, filed May 19, 1998 now U.S. Pat. No.6,068,609. U.S. application Ser. Nos. 09/363,234 and 09/314,052 arepending as of the date of filing of this application. The specificationsof U.S. application Ser. Nos. 09/363,234 and 09/314,052 are incorporatedherein by reference in their entireties.

Other related applications are being filed on even date herewith. Theyare “Method and Apparatus for Delivering an Agent to the Abdomen”, Ser.No. 10/960,148, filed Oct. 7, 2004; “Method and Apparatus for Deliveringan Agent to the Abdomen”, Ser. No. 10/960,826, filed Oct. 7, 2004; and“Method and Apparatus for Delivering an Agent To the Abdomen”, Ser. No.10/960,188, filed Oct. 7, 2004.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to treating gases delivered into body cavities,spaces or body surfaces of an animal. More specifically, it relates to adevice for, and method of, treating gases with one or more agents to becarried by the gas stream to an animal.

2. Related Art

The delivery of gas into the body of a patient is well known for manypurposes. Gas is delivered into a body cavity, such as the abdomen, todistend a compliant surface or create pressure for a specific purpose.Distention of the abdomen using gas creates a pneumoperitoneum thatachieves a space in which one can examine, repair, remove and surgicallymanipulate. The space created by gas insufflation is a basic componentof laparoscopic surgery. Within the space of the body created by the gasflow and pressure, tissue surfaces and organs can be visualized safelyand instruments placed that are used for diagnostic and therapeuticpurposes. Examples of such uses include, but are not limited to,coagulation, incision, grasping, clamping, suturing, stapling, moving,retracting and morcelizing. The quality of the gas stream can bemodified and conditioned by filtering, heating and hydrating. U.S. Pat.No. 5,411,474 and the aforementioned U.S. patent application disclosemethods for conditioning gas in this matter.

There is room for further improvement and advancement. During aprocedure that instills gas to a body cavity, body space or bodysurface, the addition of pharmacologically active or inert materials(organic or inorganic) can enhance tissue healing, reduce infection,reduce adhesion formation, modify the immunologic response, treatneoplasm, treat specific disease processes, reduce pain and assist indiagnosis. It is desirable to provide an apparatus and method suitablefor treating gas in such a manner.

SUMMARY OF INVENTION

Briefly, the present invention is directed to a method and apparatus fortreating gas with one or more agents for delivery to a body cavity, bodyspace or body surface. The gas is received into the apparatus from a gassource. The apparatus comprises a housing defining at least one chamberhaving an entry port and an exit port, the entry port for receiving agas stream from a gas source. A quantity of one or more agents isreleased into the chamber to be admixed in the gas stream that isdelivered to the animal by a delivery device. The gas stream isoptionally humidified and/or heated in the housing.

The above and other objects and advantages of the present invention willbecome more readily apparent when reference is made to the followingdescription taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of an apparatus according to the presentinvention.

FIG. 2 is a cross-sectional view of the gas treater of the apparatusaccording to the present invention.

FIG. 3 is schematic diagram of a gas treater housing according to anembodiment of the present invention comprising a plurality of distinctchambers.

FIG. 4 is an end view of the gas treater housing according to theembodiment of FIG. 3.

FIG. 5 is an internal view of the gas treater housing according toanother embodiment featuring one or more bag members inside the housing.

FIG. 6 is an internal view of the gas treater housing according to stillanother embodiment featuring one or more bag members outside thehousing.

FIG. 7 is an internal view of the gas treater housing according to yetanother embodiment featuring a tube member disposed within the housingand having a restrictive opening at a distal end thereof.

FIG. 8 is an internal view of the gas treater housing according toanother embodiment featuring a tube member disposed within the housingand having a plurality of openings on a length portion thereof.

FIG. 9 is a schematic diagram of still another embodiment featuring aninkjet printhead for controllably releasing a quantity of one or moreagents into the chamber of the gas treater housing.

FIG. 10 is a schematic diagram of a heating element used in the gastreater.

FIG. 11 is a cross-sectional view of the gas treater chamber and showingthe fluted gas inlet and outlet of the chamber.

FIG. 12 is an internal view of a gas treater housing showing a containerfor releasing a quantity of a solid phase agent into the chamber.

FIG. 13 is a view of a gas treater housing, similar to FIG. 12, butshowing the container positioned outside of the chamber.

FIG. 14 is a schematic diagram showing a circuit for controlling thetemperature of the gas and for monitoring the humidity of the gas.

FIG. 15 is a schematic diagram showing a circuit for monitoring humidityof the gas according to an alternative embodiment.

FIG. 16 is a schematic diagram of an alternative embodiment of thepresent invention, which can deliver treated or untreated gas and anagent into body cavities, spaces, or surfaces.

FIG. 17 is a schematic diagram of a further alternative embodiment ofthe present invention which can deliver treated or untreated gas and anagent into body cavities, spaces, or surfaces.

FIG. 18 is a schematic diagram of a further alternative embodiment ofthe present invention which can deliver treated or untreated gas and anagent into body cavities, spaces, or surfaces.

FIG. 19 is a schematic diagram of a further alternative embodiment ofthe present invention which can deliver treated or untreated gas and anagent into body cavities, spaces, or surfaces.

FIG. 20 is a schematic diagram of a further alternative embodiment ofthe present invention which can deliver treated or untreated gas and anagent into body cavities, spaces, or surfaces.

FIG. 21 is an elevational view showing how an agent may be introducedinto the agent chamber used in some embodiments of the invention.

FIG. 22 is an elevational view showing another way in which an agent maybe introduced into an agent chamber.

FIG. 23 is an elevational view showing still another way in which anagent may be introduced into an agent chamber.

FIG. 24 is an elevational view showing still another way in which anagent may be introduced into an agent chamber.

FIG. 25 is an elevational view showing how a syringe may be used as anagent chamber in the present invention.

FIG. 26 is an elevational view showing how a pump may be used as anagent chamber in the present invention.

FIG. 27 is an elevational view showing how a pressurized chamber may beused as an agent chamber in the present invention.

FIG. 28 is an elevational view showing how a bag may be used as an agentchamber in the present invention.

FIG. 29 is an elevational view showing how a piezoelectric chamber maybe used as an agent chamber in the present invention.

FIG. 30 shows a further embodiment of the present invention.

FIG. 31 is an elevational view of a two inlet trocar forming part of thepresent invention.

FIG. 32 is a modification of the construction shown in FIG. 31 FIG. 33is a further modification of the construction shown in FIG. 31.

FIG. 34 is a flow chart showing a series of steps that may be used inoperating various embodiments of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Definitions

As used in the claims, “a” can mean one or more.

As used herein, “a predetermined temperature” or “a predeterminedtemperature range” is one that has been preset or programmed by the userduring a procedure. For example, a desirable temperature range may bephysiological body temperature, i.e., approximately 35-40° C. Asexplained hereinafter, the temperature of the gas may be adjusted by a“dial” type or other similar adjustment.

As used herein, the term “humidifying solution” means water, normalsaline, lactated Ringers, any buffered liquid or solution, an aqueoussolution, a non-water based solution, a combination of water ornon-water solutions and other substances, or a gel substance containingwater or non-water solutions and other substances.

As used herein, the term “agent” means any organic substance, inorganicsubstance, inert or biologically active substance of pharmacologicmaterial, that may effect or enhance tissue healing, reduce infection,reduce adhesions formation, modify the immunologic response, treatspecific disease processes, reduce pain or be used for any therapeuticor diagnostic purpose. This includes materials in solid, liquid or gasphase, and materials that are water (aqueous) based, colloid andnon-colloid suspensions, mixtures, solutions, hydrogels, lyophilizedmaterials, hydrophobic, hydrophilic, anionic, cationic, surface activeagents, surgical adjuvants, anticoagulants, antibiotics, immunologicstimulators, immunologic suppressants, growth inhibitors, growthstimulators, diagnostic materials, anesthetic agents, analgesic agents,and materials by themselves or dissolved or based in other materials,such as, but not limited to, alcohols, ethers, esters, lipids andsolvents. The agent can be dry, such as in a power form. Any materialthat can be carried by the flow of gas into a body cavity or onto asurface for therapeutic or diagnostic purposes can be delivered inaccordance with this invention. It is not intended to limit the presentinvention to the above examples of agents. Furthermore, the gas streammay be treated with any type or combination of agents in accordance withthe present invention. An example is to treat the gas stream with ahumidifying solution for hydration to prevent desiccation, an antibioticto reduce infection, an anti-inflammatory to reduce inflammation and ananti-adhesive to reduce adhesions and improve healing. Agents such asthose sold under the trademarks Adept manufactured by ML Laboratories,Adcon manufactured by Gliatech and Atrisol manufactured by AtrixLaboratories can be used to reduce adhesions.

As used herein, the term “gas” includes any gas or combination ormixture of gases in any proportion that occurs naturally or can bemanufactured or placed or created in a container.

The term “treating” used in connection with treating of the gas streammeans to inject or release one or more agents into the gas stream sothat the gas stream is a fume or dust in the case of a solid phaseagent, or a mist or spray in the case of a liquid phase agent. In someembodiments, such as where the agent is in liquid form, the agent iswicked off or dislodged from a container. In other cases, the agent isinjected or released into the gas stream. In general, the gas stream tobe treated with one or more agents is also humidified.

The terms “cavity” or “space” mean any body cavity or space includingthe interthoracic cavity, the pericardium, the peritoneal cavity orabdomen, plural cavity, knee space, shoulder space, eyeball, stomach andlung.

The term “aerosol” means a suspension of liquid or solid particles in agas.

The term “spray” means a jet of liquid dispersed by a sprayer.

The term “mist” means liquid in the form of particles suspended in agas.

The term “fog” means vapor condensed to fine particles of liquidsuspended in a gas.

The term “vapor” means a gas dispersion of molecules of a substance.

The basic tenet of the present invention is to treat a flowing gasstream with one or more agents so that the agent(s) actively orpassively are injected into the gas stream and are made part of the gasstream as a result of the dynamics of flow, vapor pressure and/or rateof evaporation. The gas stream thereby is modified to contain additivesthat are determined desirable by the user for purposes of enhancing theoutcome of a gas delivery event in connection with, for example, aparticular treatment or diagnostic procedure or prevention.

The term “body surface” means any surface of the body, whether internalor external, and whether exposed naturally or by way of surgicalprocedure.

Referring to FIG. 1, the apparatus for treating or conditioning gas isshown generally at reference numeral 100. The apparatus 100 is adaptedto receive gas from a gas regulator 10 (high or low pressure, high orlow flow rate), such as an insufflator. The apparatus comprises a gastreater 120, an optional filter 110 and an optional control module 140.Tubes are provided to connect the various components of the apparatustogether. Specifically, a first tube segment 160 connects the outlet ofthe gas regulator 10 to the inlet tubing of the filter 110 via a maleLuer lock 166 or any appropriate adapter compatible with the insufflatoroutlet port. A second tube segment 162 connects the outlet of the filter110 to the inlet of the gas treater 120. A third tube segment 164connects the outlet of the gas treater 120 by a male Luer lock 168 (orother appropriate fitting adapter) to a gas delivery device (not shown),such as a trocar, Veres needle, endoscope or a tube that enters a bodycavity or space that delivers the treated gas into the body of ananimal. Alternatively, if the gas is to be delivered to a body surface,the gas delivery device may be shaped, formed or otherwise configured todirect or spread the flow of gas onto a surface.

The tubing of the tube segments 160, 162 and 164 is preferably flexibleand sufficiently long to permit the gas regulator 10 and control module140 to be placed at a convenient distance from an animal undergoingprocedure requiring gas delivery. For applications of the apparatus 100where the temperature of the gas stream should be within a desired rangewhen delivered, the gas treater 120 is preferably placed immediatelyadjacent to that location where the gas is to be delivered.

The filter 110 is an optional element and consists of a high efficiency,hydrophobic filter (for example Gelman Sciences Metricel M5PU025, havinga pore size preferably small enough to exclude all solid particles andbacterial or fungal agents that may have been generated in a gas supplycylinder or the gas regulator 10 (i.e., 0.5 micron or less andpreferably about 0.3 micron). A preferable filter is a hydrophobicfilter, such as a glass fiber-type filter, e.g., Metrigard by GelmanSciences or Porous Media Ultraphobic filter, Model DDDF 4700 M02K-GB.Other suitable filters include polysulfone (Supor, HT Tuffrin, GelmanSciences) and mixed cellulose esters (GN-6 Metricel, Gelman Sciences),for example. Decreasing the pore size of filter 110 below 0.1 microncauses a concomitant increase in pressure drop of gas, and thus flowrate is reduced significantly. If the procedure to be performed requiresa relatively high pressure and/or flow rate of gas to the animal, suchas laparoscopy, the pore size should preferably not decrease below 0.2micron. A hydrophobic filter is preferable to a hydrophilic one, as ahydrophobic filter is less likely to tear under water pressure caused byaccidentally suctioning or siphoning peritoneal or irrigation fluids.

In some applications, it is desirable that the gas treater 120 beconnected immediately adjacent to a gas delivery device so that the gastravels a minimum distance from the outlet of the gas treater 120 to theconduit or connection to the interior of an animal. The purpose of thisarrangement is to allow gas to be delivered to the animal while still ata temperature and water content sufficiently close to the physiologicalinterior body temperature or other body surface. That is, for someapplications, the apparatus according to the invention preventsthermodynamic cooling of gases in transit to the animal, because itprovides a highly efficient treatment chamber that, as a result of itsefficiency, can be quite compact and thus be positioned very near to theanimal.

The control module 140 is contained within an electrical housing 210 andis connected to the gas treater 120 by several wire pairs containedwithin an insulated electrical cable 170. In particular, the cable 170has a connector 172 at one end that electrically connects into a circuitconnector 212 of the housing 210 for the control module 140, and at theother end it is electrically connected to the gas treater 120 by asealed electrical feed through 174. The cable 170 is attached to thetube segment 162 by a plastic tape or clip 176. Alternatively, the cable170 is attached to the tube segment 162 by heat seal, extrusion,ultrasonic welding, glue or is passed through the interior of tubesegment 162.

The control module 140 and associated components in the gas treater 120are preferably powered by an AC-DC converter 180. The AC-DC converter180 has an output that is connected by a plug connector 182 into a powerreceptacle 214 of the circuit within the control module 140, and has astandard AC wall outlet plug 184 that can be plugged into standard ACpower outlets. For example, the AC-DC converter 180 is plugged into anAC power strip that is provided on other equipment in an operating room.Alternatively, electrical power for the apparatus is provided by abattery or photovoltaic source. Another alternative is to providecircuitry in the control module 140 that operates on AC signals, asopposed to DC signals, in which case the control module 140 could bepowered directly by an AC outlet. The control module 140 and the heatingand hydrating components inside the gas treater 120 will be described inmore detail hereinafter.

In some embodiments, the gas treater 120 has a charging port 190 that iscapable of receiving a supply of an agent and/or humidifying solution.For example, a syringe 200 containing a predetermined volume ofliquid-based agent is introduced into the charging port 190 to inject itinto the gas treater 120 for an initial charge or re-charge thereof. Theapparatus 100 may be sold with the gas treater 120 pre-charged with asupply of an agent and/or humidifying solution such that an initialcharge is not required for operation.

Turning to FIG. 2, the gas treater 120 will be described in greaterdetail. The gas treater 120 comprises a housing 122 having an (entryport) gas inlet 124 and an (exit port) gas outlet 126. The housing 122defines a chamber 128 that contains a treatment subchamber for treatingthe gas supplied through the inlet with an agent, and in someembodiments, contains elements for substantially simultaneously heatingand hydrating (humidifying), as well as means 136 for sensing thetemperature of the gas and means 138 for sensing the relative humidityof the gas as it exits the chamber 128.

Specifically, in the embodiment of FIG. 2, within the chamber 128, thereis provided a subchamber that comprises of one or more layers ofliquid-retaining or absorbing padding or sponge material, shown atreference numerals 130, 131 and 132. It should be understood that thenumber, spacing and absorbency of the liquid-retaining layers 130, 131and 132 varies according to specific applications. Three layers areshown as an example. The material of the layers 130, 131 and 132 can beany desirable liquid retaining or absorbent material, such as arayon/polyester formed fabric (e.g., NU GAUZE™, manufactured and sold byJohnson & Johnson Medical, Inc.). The pore size of the selected materialshould be chosen according to a balance of liquid-retaining capabilitiesand low pressure drop considerations. The larger the pore size, thegreater the liquid retention capability for gas contact for aerosolizingthe gas.

Other forms of the treatment subchamber may consist of an empty chamber,a subcontainer or subchamber of liquid within the chamber 128 (withoutabsorbent layers) having a semi-permeable membrane on opposite ends toallow gas to pass there through. The agent in the chamber is optionallyheated by a heating jacket placed around the chamber.

The heating means in the gas treater 120 consists of at least oneheating element 134 positioned in the housing, such as between theabsorbent layers 130 and 131. The heating element 134 is an electricallyresistive wire, for example. The heating element 134 is placedpreferably between absorbent layers or en-meshed within the layers ofmaterial (in the fabric). The heating element 134 heats the gas suppliedthrough the inlet, under control of a heat control signal supplied bythe control module 140, substantially simultaneous with the treatment ofthe gas as the gas passes through the chamber 128. Additional heatingelements may be disposed within the chamber.

In order to sense the temperature and humidity of the gas as it exitsthe gas treater 120, a temperature sensor 136 and a relative humiditysensor 138 are provided. The temperature sensor 136 may be providedanywhere within the flow of gas in the chamber 128, but is preferablypositioned on the downstream side of the heating element 134 betweenliquid-retaining layers. The temperature sensor 136 is a thermistor (forexample, Thermometrics MA100 Seres chip thermistor, or ThermometricsSeries BR23, Thermometrics, Inc., Edison, N.J.). It is preferable thatthe temperature sensor 136 be accurate to within about 0.2° C. In thepresent invention, the temperature of the gas is preferably sensed afterthe gas has been treated (and optionally humidified) so that any changein the temperature of the gas as it is treated is corrected at thatpoint in the apparatus, thereby compensating for enthalpy changes.

The humidity sensor 138 is positioned in the flow path of gas exitingthe chamber 128, preferably downstream from the heating element 134either between liquid-retaining layers or on the downstream side of theabsorbent layers, proximate the exit port 126 of the housing 122. Thehumidity sensor 138 is preferably not in contact with a layer. FIG. 2shows the humidity sensor 138 distal to the absorbent layers, separatedfrom the liquid-retaining layer 132 by a porous mesh (plastic or metal)layer 133 that extends across the interior of the housing 122. Thehumidity sensor 138 actually is generally not in contact with the porousmesh layer 133, but is spaced there from as well. The humidity sensor138 is, in one embodiment, a humidity-sensitive capacitor sensor, suchas a capacitive humidity sensor manufactured by Philips Corporation,which changes capacitance in response to humidity changes. The humiditysensor 138 measures the relative humidity of the gas as it passesthrough the chamber 128 to enable monitoring of the gas humidity, and inorder to provide an indication of the amount of humidifying solutionremaining in the gas treater 120, i.e., in layers 130, 131 and 132. Aswill be explained hereinafter, in one embodiment, a timer/dividerintegrated circuit (IC) 145 (FIG. 5), is connected to the humiditysensor 138 and is preferably disposed within the housing 122 togetherand substantially co-located with the humidity sensor 138. Other meansof determining the humidity of the gas are well within the scope of thepresent invention.

One way to treat a gas stream with one or more agents using theembodiment of the gas treater 120 shown in FIG. 2 is to inject from asyringe 200 a liquid-based agent into the chamber 128 through thecharging port 190 for absorption onto one of the layers 130-132. Whenthe gas stream flows over the layers 130-132, the gas stream will becometreated with agent and thereby carry the agent out of the gas treater120 into an animal. Depending on the dimensions and type of absorbentpad or pads used, there is a capacity to the amount of agent that can beintroduced into the chamber 128. The size of the chamber 128 can beincreased to allow for larger pads, and therefore greater capacity.

Several additional embodiments of the invention will now be described inconjunction with FIGS. 3-9, and 12-15. In these embodiments, otherconfigurations of the housing 122 of the gas treater 120 are describedthat are useful to treat the gas stream flowing through the gas treaterhousing 122 with one or more agents. These embodiments show differenttypes of containers for containing an agent and releasing it into thegas stream in a chamber of the gas treater 120.

FIGS. 3 and 4 illustrate an embodiment for the gas treater housing 122featuring multiple chambers, for example, three chambers 128A, 128B and128C that extend a certain length portion (not necessarily all) of thehousing 122. These chambers are separated by walls or partitions 202,204 and 206. Associated with each chamber 128A, 128B and 128C is acharging port 190A, 190B and 190C, respectively to receive a supply ofagent from a respective source, such as an external bag, syringe, etc.The agent is delivered under pressure into a chamber through itsrespective charging port, or is wicked off from a small opening of a bag(FIGS. 5 and 6) placed through the charging port into a chamber.Alternatively, within each chamber 128A, 128B and 128C is one or moreabsorbent pads or layers similar to that shown in FIG. 2, onto which aquantity of an agent is absorbed. Still a further alternative is toprovide a separate semi-permeable membrane in each chamber filled with adifferent agent.

Each of the chambers can be charged with a different agent. For example,chamber 128A may be charged with a humidifying solution, chamber 128Bmay be charged with agent A and chamber 128C may be charged with agentB. Though not shown in FIGS. 3 and 4, it should be understood that theheating elements, temperature sensor and humidity sensor shown in FIG. 2may optionally be included in their various configurations in theembodiment of the housing shown in FIGS. 3 and 4. In the embodiment ofFIGS. 3 and 4, when the gas stream flows through the housing 122, thegas stream wicks off or dislodges the humidifying solution from chamber128A, is mixed with agent A from chamber 128B and is mixed with agent Bfrom chamber 128C. Thus, the gas stream that exits the housing 120 ishydrated and treated with the agents, for delivery to an animal.

FIGS. 5 and 6 illustrate another embodiment where the agents to becarried by the gas stream are contained within bags. In FIG. 5, thereare, for example, two bags 220 and 230 each of which are to contain aquantity of an agent. The apparatus may be shipped with the bags 220 and230 pre-loaded or pre-charged with a quantity of agents, or they may befilled with a quantity of agents prior to use. The bags 220 and 230 areformed of flexible material such as, polyethylene or other similarmaterial. In one configuration, the bags 220 and 230 are formed ofsemi-permeable membrane material such that the agent contained thereincan be wicked off by the flowing gas stream over the surface of the bagsthrough the housing 122. In another configuration, at the end of eachbag 220 and 230 inside the housing 122 is a restrictive orifice, nozzleor hole 222 and 232, respectively, such as a spray hole or atomizer holeto allow for contact with the gas stream to be admixed therewith. At theother end of each bag 220 and 230 is an optional charging port 224 and234, respectively, to allow the introduction of a quantity of an agentinto the bags 220 and 230. Openings are made in the housing 122 to allowa length of the bags 220 and 230 to pass there through and into thechamber.

As the bags are filled, they expand inside the chamber 128. The pressureof the quantity of agent in the bags 220 and 230 and/or capillary actionat the holes 222 and 232 forces the agent to drip out of the holes 222and 232 to be wicked off or dislodged by the flowing gas stream throughthe chamber 128 and carried out of the exit port of the housing 122. Inthe configuration where the bags 220 and 230 are formed of asemi-permeable membrane material, the pressure of the quantity of agentin the bags facilitates the wicking off of the agent through themembrane. The bags 220 and 230 are deployed within the chamber 128 sothat when they are filled, they expand and are substantially confined toa predetermined region of the chamber so as not to interfere with gasflow over the other bag. For example, a heating coil 124 or an absorbentpad can be used to separate the bags 220 and 230 in the chamber 128.

FIG. 5 shows only two bags 220 and 230, but it should be understood thatone or any number of bags may be suitable depending on the number ofagents to be carried by the gas stream.

FIG. 6 shows a variation of the embodiment of FIG. 5 wherein the bags220 and 230 are located on the outside or exterior of the housing 122.In this configuration, openings are made in the housing 122 and theholes 222 and 232 of the bags are located just inside the housing 122 atthese openings. The agents bead out of the holes 222 and 232 and arewicked off or dislodged by the flowing gas stream through the chamber128. In addition, there will be a natural tendency for the agent in thebags 220 and 230 to enter the flowing gas stream from the holes 222 and232 due to the change in vapor pressure. Because the gas stream isrelatively dry and by contrast, the agent in the bags 220 and 230 mayhave some degree of moisture, a natural mechanism occurs by which themoist agent will wick out of the bags in an attempt to reach a vaporpressure equilibrium. The greater the rate of flow of the gas stream,the less of the agent in the bags 220 and 230 that will bead into thegas stream. The same theory of operation applies to the embodiment ofFIG. 5.

Even if deployed on the outside of the housing 122, the bags 220 and 230can be filled through their respective charging ports 224 and 234 in thesame manner as described in conjunction with FIG. 5. The number of bagsmay vary on a particular application, and two are shown in FIGS. 5 and 6only as an example. All other features concerning the heating,humidification and sensing in the housing 122 are applicable to theembodiments shown in FIGS. 5 and 6.

A still further variation on the embodiments of FIGS. 5 and 6 is toprovide the optional tubing member 250 that extends from a bag to anoptional absorbent pad 130 that is positioned within the housing 122.

Further embodiments for deploying one or more agents into the gas streamare shown in FIGS. 7 and 8. FIG. 7 shows an elongated tubing member 300that is disposed in the chamber 128 of the housing 122. The tubingmember 300 is extremely long and winds throughout the chamber 128; FIG.7 is over-simplified in this respect. The tubing member 300 is, forexample, a polyamide tubing product manufactured by MicroLumen of Tampa,Fla. The important characteristics of the tubing material are that thesides or walls of the tubing member 300 are as thin as possible so thatthe volume of agent that the tubing member 300 can carry is maximized.At the tip or end of the tubing member 300 is a restrictive orifice orhole 310 through which the agent may bead and be wicked off or dislodgedinto the gas stream, then multiple tubing members each containing adifferent agent is provided. A charging port 312 is also provided on theproximal end of the tubing member 300 just outside the housing 122 tosupply a quantity of the agent into the tubing member 300.

FIG. 8 illustrates a variation of the embodiment shown in FIG. 7,wherein a tubing member 400 is provided that includes one or a pluralityof holes or perforations 410 along the length of the tubing member 400through which the agent is allowed to release into the chamber 128. Thegas stream flowing through the chamber 128 will wick off or dislodge theagent from the holes 410 and carry the agent in the gas stream. Thetubing member 400 has a charging port 412 similar to charging port 300for tubing member 300. Also, multiple tubing members 400 may be providedin the chamber to release multiple types of agents into the gas stream.The length of each tubing member 400 and the quantity and size of theholes 412 therein may be selected to control the rate at which differentagents from different tubing members 400 are wicked off or dislodged bythe gas stream flowing through the chamber 128.

In the embodiments shown in FIGS. 2-8, the size of the chamber 128 ofthe gas treater housing 122 may vary depending on the intended use, gasflow, type of agent, whether and how many absorbent pads are provided,etc. There is no limit, either relative small, or relatively large, tothe size of the chamber for purposes of carrying out the presentinvention.

Turning to FIG. 9, yet another embodiment is shown wherein an inkjetprinthead cartridge 500 is used to release vapor bubbles containing aquantity of one or more agents into the chamber 128 of the housing 122.The inkjet printhead cartridge 500 may be one of any known inkjetprintheads such as those used in inkjet printers sold byHewlett-Packard, Canon, etc.

As is well known in the art, an inkjet printhead cartridge, such as thatshown at reference numeral 500, comprises a reservoir 510, a printhead520 and a plurality of contact pads 530. Conductive traces in thecartridge 500 are terminated by the contact pads 530. The contact padsare designed to normally interconnect with a printer so that the contactpads 530 contact printer electrodes that provide externally generatedenergization signals to the printhead 520 to spray ink onto paper.Thermal inkjet printheads create vapor bubbles by elevating the inktemperature, at the surface of a plurality of heaters, to a superheatlimit. This same process can be used to create vapor bubbles of one ormore agents. The printhead 520 comprises a plurality of nozzles 522 fromwhich the vapor bubbles are released when heaters are energized to heatthe quantity of agent contained in the reservoir.

According to the present invention, the inkjet printhead cartridge 500is connected to a control circuit 600 by way of connector 610 havingcontacts to match the contact pads 530. The control circuit 600 may becontained within the control module 140 shown in FIG. 1 and coupled tothe cartridge 500 by one or more electrical conductors contained in theelectrical cable 170. The reservoir 510 is filled with a quantity orvolume of one or more agents to be released into the chamber 128. Forexample, a color inkjet printhead cartridge contains multiple chambersor reservoirs for each of three colors of ink. Using this same type ofdevice, an ink-jet printhead cartridge may contain a quantity or volumeof several different agents to be separately or simultaneously deliveredinto the chamber in controlled amounts. The control circuit 600generates appropriate control signals that are coupled to the cartridge500 via the connector 610 to drive the heaters in the printhead 520 andrelease vapor bubbles of one or more agents into the chamber from thenozzles 522.

When the one or more agents are released into the chamber 128, the gasstream that flows through the chamber and carries the agent out the exitport of the housing 122 and into the animal. Each of the differentagents can be released into the chamber 128 at different rates orvolumes. Furthermore, it is possible that a different inkjet printheadcartridge is provided for each of separate subchambers inside chamber128 to keep the agents from mixing for a period of time before deliveredinto the animal.

Referring back to FIG. 2, electrical connections to the componentsinside the housing 122 of the gas treater 120 are as follows. A groundor reference lead (not specifically shown) is provided that is connectedto each of the temperature sensor 136, heating element 134 and humiditysensor 138-timer/divider 145. A wire 175 (for a positive lead)electrically connects to the hearing element 134 and a wire 176 (for apositive lead) electrically connects to the temperature sensor 136. Inaddition, three wires 177A, 177B and 177C electrically connect to thehumidity sensor 138-timer/divider circuitry, wherein wire 177A carries aDC voltage to the timer/divider 145, wire 177B carries an enable signalto the timer/divider 145, and wire 177C carries an output signal (data)from the timer/divider 145. All of the wires are fed from the insulatedcable 170 into the feedthrough 174 and through small holes in thehousing 122 into the chamber 128. The feedthrough 174 is sealed at theopening 178 around the cable 170.

The charging port 190 is attached to a lateral extension 139 of thehousing 122. The charging port 190 comprises a cylindrical body 192containing a resealable member 194. The resealable member 194 permits asyringe or similar device to be inserted there through, but seals aroundthe exterior of the syringe tip. This allows a volume of liquid agent orhumidifying solution to be delivered into the chamber 128 withoutreleasing the liquid already contained therein. The resealable member194 is, for example, Baxter InterLink™ injection site 2N3379.Alternatively, the charging port may be embodied by a one-way valve, asealable port, a screw cap, a cap with a slit to permit the introductionof a syringe or other device, such as a Safeline™ injection site, partnumber NF9100, manufactured by B. Braun Medical Inc., or any othercovering material or member capable of permitting the introduction of asyringe and preventing the backflow of contained liquid or gas. Thecontrol module 140 will issue a warning when the humidity of the gasbeing treated by the gas treater 120 drops below a predetermined or userprogrammable relative humidity, as explained hereinafter.

As an alternative, or in addition to the sensing and monitoring featuresdescribed above, a backup or reserve supply container for liquid agentand/or humidifying solution is provided. Referring back to FIG. 1, oneform of a backup supply container is a container 800 that hangs free ofthe apparatus 100 and is connected with an access tubing 810 to thecharging port 190. The container 800 is, for example, a bag such as anintravenous fluid bag and the access tubing 810 is an intravenous typetubing.

Another form of a backup supply container is a container 850 thatattaches to a portion of the apparatus 100. For example, the container850 is a reservoir tube, bag, syringe or tank that is attached to thetubing segment 162 or is strapped or fastened to the tubing segment 162close to the gas treater 120. Another alternative would be to strap orfasten it to the outside of the housing 122 of the gas treater 120. Thecontainer 850 is connected to an access tubing 860 that connects intothe charging port 190, similar to access tubing 810 described above.

Access tubing 810 and 860 have a penetrating member (not shown) at theirdistal ends to penetrate the charging port 190 to gain access to thechamber 128 of the gas treater housing 122. Alternatively, instead ofthe access tubing 860, the container 850 has at the end proximate thecharging port 190 a tip member similar to that of the syringe 200 topenetrate and directly couple to the charging port 190.

The containers 800 and 850 can be pre-charged or charged prior to useaccording to techniques well known in the art. For example, container850 has an injection site 862 to enable injection of liquid into thecontainer 850.

Preferably, the access tubing 810 or 860 of the backup supply containers800 and 850, respectively, (or the integral penetrating tip of thecontainer 850) extend far enough through the charging port 190 so as tomake contact with one of the layers 130-132 so that the liquid thereinis wicked off on to one of the layers 130-132 due to capillary forces.Alternatively, the access tubing 810 or 860 (or integral penetrating tipof the container 850) stops short of one of the layers 130-132, and thepressure differential created by the flowing gas stream through thehousing 122 will wick off the liquid agent and/or humidifying solutionfrom the end of these members to contribute to the treatment of the gas.

With reference to FIG. 2, another variation is to provide an extensiontube 870 that leads from the charging port 190 where the access tubing810 or 860 (or the integral penetrating tip member of the container 850)terminates, to the treatment subchamber inside the chamber 128, i.e., tocontact one or more of the layers 130-132. Liquid agent and/orhumidifying solution is continuously wicked out from the end of theextension tube 870 onto one of the layers 130-132.

In either form of the backup supply container, the basic principle isthe same. The backup supply container provides is coupled through thecharging port 190 to the treatment subchamber inside the chamber 128 toconstantly replenish the treatment subchamber, e.g., one or more of thelayers 130, 131 or 132. Consequently, the treatment subchamber will havean initial amount of liquid agent and/or humidifying solution(pre-charged or charged prior to use) and a backup supply from thebackup supply container is constantly supplied to the treatmentsubchamber to constantly replenish it as gas flows through the chamber.The overall time of sufficient gas humidification and/or treatment isthereby lengthened to a duration that is suitable for all or nearly allgas delivery applications. As a result, there is no need to be concernedabout decreasing humidity of the gas delivered. The backup supplycontainer acts as a backup to provide gas humidification and/ortreatment for an entire procedure. Therefore, some forms of theapparatus 100 need not include the humidity and temperature sensing andmonitoring features, or the recharge alert, described herein. Thefeatures provide another type of backup that may be useful in certainapplications, instead of, or in addition to the backup supply container.

The desirable width and diameter of the gas treater is dependent uponmany factors, including the intended use, the rate of gas flow from thegas source and the pressure desired to be maintained, which is affectedmore by the diameter of chamber 128 than by its length. A person ofordinary skill in the art, given the teachings and examples herein, canreadily determine suitable dimensions for chamber 128 without undueexperimentation. It should also be noted, however, that upon activatingthe apparatus or changing the demand on the apparatus (e.g., flow rateor pressure), there is a lag time of only several tenths seconds forsensing the temperature of gas and adjusting the hearing element toachieve the proper gas or desired temperature. Such a fast start-up timeis extremely beneficial.

Referring to FIG. 10, the heating element 134 is shown in more detail.The heating element 134 is an electrically resistive wire that isdisposed in the housing 128 in a concentrical coil configuration havinga number of turns, such as 6-8 turns. Alternatively, a second heatingelement 134′ is provided that is arranged with respect to the heatingelement 134 such that its coils are offset from those of the firstheating element, relative to the direction of gas flow through thechamber. If two or more heating elements are employed, they arepreferably spaced from each other in the chamber of the gas treater byapproximately 3-4 mm. The first and second heating elements 134 and 134′can be coiled in opposite directions relative to each other. Thisarrangement allows for maximum contact of the gas flowing through thechamber with a heating element. Other non-coiled configurations of theheating element 134 are also suitable.

Turning to FIG. 11, another feature of the gas treater 120 isillustrated. At the inlet and/or outlet of the housing 122, flutedsurfaces 123 may be provided to facilitate complete dispersion of gas asit is supplied to the gas treater 120. This improves the fluid dynamicsof the gas flow through the chamber 128 to ensure that the gas isuniformly heated and humidified as it flows through the chamber 128.

FIGS. 12 and 13 illustrate embodiments of the apparatus to treat the gasstream with a solid phase agent. FIG. 12 shows a container 700 of asolid phase agent, such as in power form, that is positioned in thechamber 128 of the gas treater housing 122. The container 700 includes acheck valve 710 and a pressurizer 720, such as a carbon dioxidecartridge. When the pressurizer 720 is activated, pressure inside thecontainer 700 is caused to rise, such that the bias of the check valve710 is overcome, releasing the agent into the chamber 128. A button 730on the exterior of the housing 122 is coupled by a wire or other meansto pressurizer 720 to activate it remotely.

FIG. 13 shows a container 700 of solid phase agent positioned outside ofthe housing 122. The check valve 710 of the container 700 is fed throughan opening in the housing 122 into the chamber 128. The button 730 foractivating the pressurizer is optionally positioned on the exterior ofthe container 700. Operation of the configuration shown in FIG. 13 issimilar to that of FIG. 12.

In the embodiment of FIGS. 12 and 13, the rate at which the solid phaseagent is released into the chamber 128 is dependent upon the pressurecreated in the container 700 by the pressurizer 720 and the size of thecheck valve 710. It may be desirable to deliver short bursts of thesolid phase agent into the gas stream, or to deliver it into the gasstream on a continuous basis. If necessary, a separate backup source ofpressure may be coupled to the container 700 to provide for longer termtreatment of the gas stream. In any case, the gas stream flowing throughthe housing 122 will carry the solid phase agent with through the exitport.

Referring to FIG. 14, the control module 140 will be described indetail. The control module 140 contains monitoring circuitry and controlcircuitry for the apparatus 100. It is understood that some forms of theapparatus 100 need not include the humidity (and heating) sensing,monitoring, temperature control and recharge alert functions. Thecontrol module 140 comprises a voltage regulator 141, a microcontroller142, an A/D converter 143, a dual operational amplifier (hereinafter“op-amp”) module 144, and a timer/divider 145. The monitoring circuitportion of the control module 140 consists of the combination of themicrocontroller 142 and timer/divider 145. The control circuit portionof the control module 140 consists of the microcontroller 142, A/Dconverter 143 and op-amp module 144. The monitoring circuit monitors therelative humidity of gas exiting the chamber based on a signal generatedby the timer/divider 145. The control circuit monitors the temperatureof the gas exiting the chamber and in response, controls electricalpower to the heating element to regulate the temperature of the gas to auser programmable or fixed temperature or temperature range. While thetemperature of the gas exiting the chamber is actively controlled, therelative humidity of the gas in the chamber is not actively controlled;rather it is monitored and an alert is generated when it drops below acorresponding threshold so that appropriate action can be taken, such asreplenishing the gas treater 120 with liquid agent or humidifyingsolution.

FIG. 14 shows that several components are preferably located within theelectrical housing 210 (FIG. 1), whereas other components are locatedwithin the housing of the gas treater 120 (FIG. 2). In particular, thetimer/divider 145 and the associated resistors R4 and R5 are preferablylocated inside the housing 122 of the gas treater 120, together with thehumidity sensor 138 in a circuit package that includes the humiditysensor 138 exposed on one or more surfaces thereof. More specifically,the timer/divider 145 is co-located with humidity sensor 138. Thisconfiguration minimizes timing error by stray wiring inductance andcapacitance (sensor kept close to active circuits of timer/divider 145).In addition, by co-locating the timer/divider 145 and humidity sensor138, the need for interconnecting wires is eliminated, thereby avoidingundesirable signal radiation.

The voltage regulator 141 receives as input the DC output of the AC-DCconverter 180 (FIG. 1), such as for example, 9V DC, that is suitable foruse by the analog components of the control module. The voltageregulator 141 regulates this voltage to generate a lower voltage, suchas 5V DC, for use by the digital components of the control module. Thecapacitor C1 at the output of the voltage regulator 141 serves to filterout any AC components, as is well known in the art. Alternatively, asuitable DC voltage is provided by a battery or photovoltaic sourceshown at reference numeral 149.

The microcontroller 142 is a PIC16C84 integrated circuit microcontrollerthat controls system operation. A ceramic resonator 146 (4 MHz) isprovided to supply a raw clock signal to pins 15 and 16 of themicrocontroller 142, which uses it to generate a clock signal for thesignal processing functions explained hereinafter.

The op-amp 144 module is coupled (by wire 176) to the temperature sensor136 (thermistor) mounted in the housing of the gas treater. The op-ampmodule 144 is, for example, a LTC1013 dual low-input-offset-voltageoperational amplifier integrated circuit that includes two op-amps,referred to hereinafter as op-amp A and op-amp B. The non-invertinginput of the op-amp A of the op-amp module 144 is pin 3, and pin 2 isthe inverting input. The output of op-amp A is pin 1. Op-amp A of theop-amp module 144 is used to buffer the output voltage of the voltagedivider formed by resistors R1 and R2. The buffered output voltage,referred to as Vx in FIG. 5, is applied to op-amp B in the op-amp module144. Op-amp B is configured as a non-inverting-with-offset amplifierwith a gain of 21.5, and also receives as input the output of thetemperature sensor 136, adjusted by resistor R3, shown as voltage Vy inthe diagram. The output voltage of op-amp B is at pin 7, referred to asVo in FIG. 5. The output voltage Vo is equal to 21.5Vy-20.5Vx, which isinversely proportional to the gas temperature in the housing of the gastreater. The output voltage Vo ranges between 0-5V DC, depending on thetemperature of the gas in the chamber.

The A/D converter 143 is an ADC 0831 integrated circuitanalog-to-digital converter that receives as input at pin 2, the outputVo of the op-amp module 144. The A/D converter 143 generates a multi-bitdigital word, consisting of 8 bits for example, that represents theoutput voltage Vo, and is supplied as output at pin 6, which in turn iscoupled to I/O pin 8 of the microcontroller 142. The microcontroller 142commands the A/D converter 143 to output the digital word by issuing acontrol signal on I/O pin 10 which is coupled to the chip select pin 1of the A/D converter 143. Moreover, the microcontroller 142 controls therate at which the A/D converter 143 outputs the digital word bysupplying a sequence of pulses on pin 9 applied to clock input pin 7 ofthe A/D converter 143. The “unbalanced bridge” values of resistors R1,R2 and R3 are chosen to produce a 0-5V DC output over gas temperaturesfrom approximately 20° C. to approximately 45° C. Since the bridge andthe reference for the A/D converter 143 are provided by the same 5V DCsource, error due to any reference voltage shift is eliminated.

The timer/divider 145 is, for example, a MC14541 precision timer/dividerintegrated circuit. The humidity sensor 138 is connected to pin 2 and toresistors R4 and R5 as shown. In response to an enable signal output bythe microcontroller 142 on pin 12 that is coupled to timer/divider pin6, the timer/divider 145 generates an output signal that oscillates at arate determined by the value of the resistor R4, the capacitance of thehumidity sensor 138 (which varies according to the relative humidity ofthe gas inside the gas treater housing) and a predetermined dividerconstant. For example, the divider constant is 256. Specifically, theoutput signal of the timer/divider 145 is a square wave oscillatingbetween 0V (“low”) and 5V (“high”) at a frequency of approximately1/[256*2.3*R4 _(t)*C_(t)]Hz, where R4 _(t) is, for example, 56 kOhms,and C_(t) is the capacitance at some time (t) of the relative humiditysensor 138 depending on the relative humidity of the gas in the chamber.For example, the humidity sensor manufactured by Phillips Electronics,referred to above, can measure between 10-90% RH (relative humidity),where C_(t) at 43% RH is 122 pF (+/−15%), with a sensitivity of0.4+/−0.5 pF per 1% RH. The output signal of the timer/divider 145appears at pin 8, which is coupled to the I/O pin 13 of themicrocontroller 142. Thus, the timer/divider 145 is essentially anoscillator circuit connected to the humidity sensor that generates anoutput signal with a frequency dependent on a capacitance of thehumidity sensor. Any oscillator circuit that can generate as output asignal whose frequency is dependent on a variable capacitance may besuitable for the timer/divider 145.

The microcontroller 142 computes a measure of the relative humidity ofthe gas inside the gas treater housing by timing or measuring acharacteristic of the output signal of the timer/divider 145.Specifically, microcontroller measures the time duration of one of thephases of the output signal of the timer/divider 142, such as the “high”phase which is approximately ½*[256*2.3*R4 _(t)*C_(t)]. This timeduration is indicative of the relative humidity of the gas in thechamber of the gas treater since the rate of the oscillation of thetimer/divider depends on the capacitance of the humidity sensor 138, asexplained above. For example, for a change in RH of 10-50% and/or 50 to90%, there is a 13% change in the duration of the “high” phase of thetimer/divider output signal. The microcontroller 142 monitors therelative humidity of the gas exiting the chamber in this manner and whenit drops below a predetermined relative humidity threshold (indicated bya corresponding predetermined change in the oscillation rate of thetimer/divider 145), the microcontroller 142 generates a signal on pin17, called a recharge signal, that drives transistor Q3 to activate anaudible alarm device, such as buzzer 147. The buzzer 147 generates anaudible sound which indicates that the relative humidity of the gas inthe gas treater has dropped below the predetermined threshold and thatit is necessary to recharge the gas treater with liquid. Thepredetermined relative humidity threshold corresponds to a minimum levelfor a desirable relative humidity range of the gas exiting the gastreater, and may be 40%, for example. The predetermined relativehumidity threshold is an adjustable or programmable parameter in themicrocontroller 142. Optionally, the microcontroller 142 may generateanother warning signal at the output of pin 7 to illuminate a lightemitting diode (LED) 148A, thereby providing a visual indication of thehumidity dropping below the predetermined relative humidity threshold inthe gas treater, and the need to recharge the gas treater 120 withliquid. Further, the microcontroller 142 generates a trouble or warningsignal output at pin 6 to drive LED 148B (of a different color than LED148A, for example) when there is either a “code fault” in themicrocontroller 142 (an extremely unlikely occurrence) or when therelative humidity of the gas in the gas treater is less than a criticalrelative humidity threshold (lower than the predetermined relativehumidity threshold), such as 10%. In either case, power to the heatingelement 134 is terminated in response to the warning signal.

The microcontroller 142 also controls the heating element 134 in orderto regulate the temperature of the gas inside the gas treater.Accordingly, the microcontroller 142 processes the digital word suppliedby the A/D converter 143 to determine the temperature of the gas insidethe gas treater housing. In response, the microcontroller 142 generatesa heat control signal on the output pin 11 that drives transistor Q1,which in turn drives the MOSFET power transistor Q2, that suppliescurrent to the heating element 134. The temperature of the gas insidethe gas treater is regulated by the microcontroller 142 so that it iswithin a predetermined temperature range as it exits the gas treater fordelivery into the body of a patient. The predetermined temperature rangethat the gas is regulated to is approximately 35°-40° C., but preferablyis 37° C. As mentioned above, when the relative humidity inside the gastreater falls below a critical threshold as determined by the monitoringcircuit portion of the control module 140, the control circuit portionin response terminates power to the heating element 134 to prevent thedelivery of warm gas that is extremely dry.

The circuitry for monitoring the relative humidity of the gas can beembodied by other circuitry well known in the art. In addition, whilethe control module 140 has been described as having a singlemicrocontroller 142 for monitoring signals representing temperature andrelative humidity of the gas exiting the chamber, and for controllingthe heating element to control the temperature of the gas, it should beunderstood that two or more microcontrollers could be used dedicated tothe individual functions. In addition, the functions of themicrocontroller 142 could be achieved by other circuits, such as anapplication specific integrated circuit (ASIC), digital logic circuits,a microprocessor, or a digital signal processor.

FIG. 15 illustrates an alternative embodiment for monitoring relativehumidity of the gas, in which a humidity sensitive resistor is used,instead of a humidity sensitive capacitor 138. The humidity sensingscheme employing a resistive humidity sensor does not require thetimer/divider circuit 145 shown in FIG. 14. The humidity sensitiveresistor 900 is located inside the gas treater housing in a suitablelocation for sensing the relative humidity of the gas stream flowingthrough the gas treater 120. A suitable humidity sensitive resistor is amodel UPS600 resistor by Ohmic, which at 45% RH is approximately 30.7 kOhms. A resistor R10 is coupled in a voltage divider configuration withthe humidity sensitive resistor 900. Three pins of the microcontroller142 couple to the voltage divider formed by resistor R10 and humiditysensitive resistor 900.

Pin 910 of the microcontroller 142 is coupled to one terminal of theresistor R10, pin 912 is coupled to one terminal of the humiditysensitive resistor 900 and pin 914 is coupled to the terminal betweenthe resistor R10 and the humidity sensitive resistor 900. The humiditysensitive resistor 900 may be a type that requires AC excitation.Accordingly, the microcontroller 142 excites the humidity sensitiveresistor 900 by applying an alternating pulse, such as a 5-volt pulse,to pins 910 and 912, such that pin 912 is “high” for a period of timeand pin 910 is low. As a result, the average excitation voltage to thehumidity sensitive resistor 900 is zero. During the time period when pin910 is “high”, the microcontroller 142 senses the humidity of the gas bydetermining if the tap voltage pin 914 is a logic “zero” or a logic“one”. If it is a logic zero (low voltage), the resistance of thehumidity sensitive resistor 900 is low, indicating that the relativehumidity of the gas is still high. If it is a logic one (high voltage),then the resistance of the humidity sensitive resistor 900 is high,indicating that the relative humidity of the gas is low. The value ofthe resistor R10 is chosen to yield a transition at pin 914 at a desiredhumidity threshold, such as 45% RH, with a 2.5 V transition from a lowvoltage to a high voltage. For example, resistor R10 is a 30 k ohmresistor. In the embodiment employing a resistive humidity sensor, amicrocontroller that is suitable is a PIC16C558 in place of themicrocontroller model referred to above in conjunction with FIG. 14.This sensing scheme can be simplified even further if a relativehumidity sensor that allows DC excitation is used. In this case, onlyone pin of the microcontroller 142 need be associated with humiditysensing.

A resistive humidity sensor has certain advantages over a capacitivehumidity sensor. It has been found that the specific type of resistivehumidity sensor referred to above can tolerate immersion in water in thegas treater 120 if a user accidentally over-fills the gas treater 120.In addition, the sensing scheme using a resistive sensor does notrequire a relatively high frequency square wave signal, which may beundesirable in some environments where the apparatus is used. Finally,the resistive sensor affords better accuracy for relative humiditysensing in some applications.

Other variations or enhancements to the circuitry shown in FIG. 14 arepossible. The type of microcontroller used can be one, such as thePIC16C715, that incorporates the functions of the A/D converter 143. ThePIC16C715 microcontroller incorporates a multichannel A/D converter. Inaddition, a more feature rich microcontroller of this type will allowfor the addition of a display, such as a liquid crystal display (LCD) orLED display. The microcontroller could generate information on aperiodic basis to be displayed to the user, such as gas temperature andrelative humidity. In addition, the microcontroller may directly drivean audible alert device, rather than indirectly driving it through atransistor as shown in FIG. 14. These are examples of the types ofmodifications or variations that are possible depending on the type ofmicrocontroller that is selected for use in the control module 140.

With reference to FIGS. 1 and 2, the setup and operation of theapparatus 100 will be described. The AC/DC converter 180 is plugged intoa 110V AC power source, such as a wall outlet or a power strip. Thecontrol module 140 is connected to the AC/DC converter 180.Alternatively, the apparatus 100 may be powered by a battery orphotovoltaic source. The heater/hydrating tubing set is then installedby attaching one end of the tube segment 160 to the outlet of theinsufflator 10 by the Luer lock 166. The tube segments 160, 162 and 164may be pre-attached to the filter 110 and the gas treater 120 forcommercial distribution of the apparatus 100. The cable 170 is installedinto the electrical housing 210 of control module 140 by the connector172.

The gas treater 120 is charged with a supply of liquid agent and/orhumidifying solution by the syringe 200. The syringe 200 is theninserted into the charging port 190 so that a needle or cannula of thesyringe 200 penetrates the resealable member 194 (FIG. 2) and the liquidis injected into the gas treater 126 to be absorbed by the absorbentlayers. The syringe 200 is then removed from the charging port 190, andthe charging port 190 seals itself. The free end of the tube segment 164is attached to a gas delivery device by the Luer lock 168 or otherappropriate connector. Alternatively, the gas treater 120 may bepre-charged with liquid, thus not requiring a charge prior to operation.

If the embodiment of FIG. 5 or 6 is employed, then the bags 220 and 230are charged (unless they are pre-charged) with a quantity of one or moreagents. Likewise, if the embodiment of FIG. 7 or 8 is employed, the tubemember 300 or tube member 400 is charged (unless it is pre-charged) witha quantity of one or more agents. The nozzles 522 of the printhead 520are positioned in alignment with an opening to the housing 122. Finally,if the embodiment of FIG. 12 or 13 is employed, the container 700 isprepared for use as described above in conjunction with FIGS. 12 and 13.

Once the gas regulator 10 is activated, it receives gas from a gassupply cylinder and regulates the pressure and flow rate of the gas,both of which can be adjusted by the operator. The pressure andvolumetric flow rate are controlled by adjusting controls (not shown) onthe gas regulator 10. Gas then flows through the tube segment 160 intothe optional filter 110 where it is filtered, and then through tubesegment 162 into the gas treater 120. In the gas treater 120, gas comesinto contact with the optional electrical heating element 134 and theoptional humidifying liquid-retaining layer(s) 130-132 which arepositioned within the flow path of the gas, as shown in FIG. 2.

Depending on which gas treater embodiment of FIG. 2-9, 12, or 13 isemployed, the gas stream is treated with a quantity of one or moreagents so that the one or more agents is carried out of the gas treater120 for delivery to an animal. For some applications and temperaturerange requirements, it may be desirable to position the gas treater 120immediately adjacent the location to which the treated gas is to bedelivered.

In the event that heating and humidification of the gas is also desiredand the appropriate components are also deployed in the gas treater 120,then in chamber 128, the gas is also simultaneously heated andhumidified to the proper physiological range by regulation of theheating element 134 and liquid content of the layers 130-132 such thatthe temperature of gas exiting chamber 128 is within a preselectedphysiological temperature range (preferably 35° to 40° C., though anydesired temperature range can be preselected), and within a preselectedrange of relative humidity (preferably above 40% relative humidity, suchas in the range of 80-95% relative humidity). If the apparatus isoperated with the gas treater 120 not charged with liquid agent and/orhumidifying solution either because the user forgot to manually chargeit before initiating operation, or the apparatus was sold without apre-charge of liquid (i.e., in a dry state), the relative humidity ofthe gas in the chamber of the gas treater 120 will be detected to bebelow the predetermined threshold and the alarm will be activated,alerting the user that the gas treater 120 requires charging of liquid.The apparatus will automatically issue an alarm to alert a user to theneed for charging the gas treater 120 with liquid agent and/orhumidifying solution, thereby avoiding further delivery of unhydratedgas into an animal.

With further reference to FIG. 5, the control module 140 monitors therelative humidity of the gas exiting the chamber and further regulatesthe temperature of the gas in the chamber 128. In particular, themicrocontroller 142 generates a recharge signal when the relativehumidity of the gas in the chamber drops below the predeterminedrelative humidity threshold, indicating that the liquid supply in thegas treater 120 requires replenishing. An audible alarm is issued by thebuzzer 147 and/or a visual alarm is issued by LED 148A to warn themedical attendant or user that the gas treater 120 requires recharging.Preferably, the microcontroller 142 continues the alarm until thehumidity in the chamber returns to a level above the predeterminedrelative humidity threshold, which will occur when the gas treater 120is recharged with liquid. Moreover, the microcontroller 142 will issue asecond alarm, such as by energizing LED 148B, when the relative humiditylevel of gas in the gas treater 120 drops below the critical relativehumidity threshold, at which point electrical power to the heatingelement 134 is terminated. In addition, the microcontroller 142 controlsthe temperature of the gas by controlling electrical power supplied tothe heating element 134.

In some cases, the controlled humidity of the gas stream is moreimportant than controlled heating. For those applications, the apparatuswould include only those components necessary to treat the gas streamwith one or more agents (according to the embodiments of FIGS. 7-13) andto humidify the gas stream. Furthermore, monitoring the humidity of thegas stream is also optional for certain applications. For example,treating the gas stream with a dry agent may not normally requireheating or humidification.

The method and apparatus of this invention can be utilized for manymedical procedures requiring the provision of heated and humidified gas.The optional filtration may also be utilized according to the sterilityof gas required for the procedure. The gas is chosen according to theprocedure to be performed and can be any medically useful gas, such ascarbon dioxide, oxygen, nitrous oxide, argon, helium, nitrogen and roomair and other inert gases. Preferable gases for endoscopy are carbondioxide and nitrous oxide. A combination of the above gases can also beused, i.e., 100% of a single gas need not be used. The procedure ispreferably endoscopy such as laparoscopy, colonoscopy, gastroscopy,bronchoscopy, and thoracoscopy. However, it may also be utilized forproviding heated and humidified oxygen or any anesthetic gases orcombination of gases for breathing, for example, or to administeranesthesia or breathing therapy. In particular, the compact size of theapparatus make the invention portable and thus suitable for usesrequiring portability. The gas delivery device that provides the directcontact to the patient should be selected according to the medicalprocedure to be performed as known to those skilled in the art. The gasthat is conditioned by the apparatus may be pressure controlled,volumetrically controlled or both.

In some cases, it is desired to supply some agents of pharmacologicmaterial, separate from other agents (which, as discussed above, couldbe pharmacologic agents) which may be supplied by the heater/hydrator120. Depending upon the agent, it may be desirable to use theheater/hydrator to humidify and heat the insufflation gas, and supplythe agent separately. Alternatively, one or more agents could besupplied using a heater/hydrator while one or more additional agentscould be supplied into the gas stream separately.

Agents can be supplied through a gas stream, for example, during alaparoscopy, colonoscopy, gastroscopy, and/or thoracoscopy, or any otherprocedure that requires distention. For example, while these proceduresare presently done under general anesthesia, where uses of therapeuticdoses of anesthesia administered, by way of example, and not oflimitation, into the abdomen during surgery, less, or no generalanesthesia may be needed, making for faster surgeries, and quickerpatient recovery. For example, an appendectomy, cholycysectomy, or tuballigation might be done without general anesthesia.

While any type of agent could be delivered using the invention, examplesof particular agents that might be delivered in a gas stream during aprocedure include anesthetic agents, analgesic agents, chemotherapyagents, anti-infective agents, and anti-adhesion agents.

Anesthetic agents include, but are not limited to, alcohol, Bupivacaine,Chloroprocaine, Levobupivacaine, Lidocaine, Mepivacaine, Procaine,Ropivacaine and Tetracaine.

Analgesic agents may include, but are not limited to, respiratory agentssuch as Excedrin, Tylenol, DayQuil, NyQuil; centrally acting analgesicssuch as, Duraclon, Ultrocet and Ultram; miscellaneous analgesics agentssuch as, Carbatrol, Hyalgan, Lidoderm, Nuropin, Neurontin, Phenegran,and Tegretol; as well as narcotics such as, Nubain, Darvocet, Dilaudid,Lortab, OxyContin, Percocet, and Vicodin.

Chemotherapy agents, also known as antineoplastic agents, may include,but not be limited to, Altretamine, Asparaginase, BCG, Bleomycinsulfate, Busulfan, Carboplatin, Carmustine, Chlorambucil, Cisplatin,Cladribine, Cyclophosphamide, Cytarabine, Decarbazine imidazolecarboxamide, Dactinomycin, Daunorubicin-daunomycin, Dexamethasone,Doxorubicin, Etoposide-epipodophyllotoxin, Floxuridine, Fluorouracil,Fluoxymesterone, Flutamide, Fludarabine, Goserelin, Hydroxyurea,Idarubicin HCL, Ifosfamide-Isophosphamide, Interferon alfa, Interferonalfa 2a, Interferon alfa n3, Irinotecan, Leucovorin calcium, Leuprolide,Levamisole, Lomustine, Megestrol, Melphalan-L-phenylalanine mustard,L-sarcolysin, Melphalan hydrochloride, MESNA, Mechlorethamine, nitrogenmustard, Methylprednisolone, Methotrexate-Amethopterin,Mitomycin-Mitomycin C, Mitoxantrone, Mercaptopurine, Paclitaxel,Plicamycin-Mithramycin, Prednisone, Procarbazine,Streptozocin-Streptozotocin, Tamoxifen, 6-thioguanine,Thiotepa-triethylene thiophosphoramide, Vinblastine, Vincristine andVinorelbine tartrate.

Anti-infective agents include those agents classed as antihelminics andantibiotics. Antibiotics may be further classified as aminoglysosides,anti-fungal antibiotics, cephalosporins, b-lactam antibiotics,chloramphenical, macrolides, penicillins, tetracyclines, miscellaneousantibiotics, antituberculosis agents, anti-virals, anti-retrovirals,antimalarials, ouinolones, sulfonamides, sulfones, urinaryanti-infectives and miscellaneous anti-infectives.

Antihelminics may include by way of example, but not of limitation to,Thiabendazole.

Aminoglycosides may include by way of example, but not of limitation to,Amikacin, Gentamicin, Neomycin, Streptomycin and Tobramycin.

Antifungal antibiotics may include by way of example, but not oflimitation to, Amphotericin B, Amphotericin B, Lipid formulation T.E.,Fluconazole, Flucytosine, Griseofulvin, Itraconazole, Ketoconazole,Nystatin, and Terbinafine.

Cephalosporins may include by way of example, but not of limitation to,Cefaclor, Cefazolin, Cefepime, Cefixime, Cefonicid, Cefotaxine,Cefpodoxine, Cefprozil, Ceftazidine, Ceftriaxone, Cefuroxime,Cephalexin, and Cephradine.

B-Lactam antibiotics may include by way of example, but not oflimitation to, Aztreonam, Cefotetan, Cefoxitin, and Imipenem/Cilastatin.

Chloroamphenicol may include by way of example, but not of limitationto, Chloramphenicol, Chloramphenicol Palmitate, and ChloramphenicolSuccinate.

Macrolides may include by way of example, but not of limitation to,Azithromycin, Clarithromycin, Erythromycin, Erythromycin Ethyl Succinateand Erythromycin Lactobionate.

Tetracyclines may include by way of example, but not of limitation to,Demeclocycline, Doxycycline, Minocycline and Tetracycline.

Miscellaneous antibiotics may include by way of example, but not oflimitation to, Bacitracin, Clindamycin, Polymyxin B, Spectinomycin andVancomycin.

Antituberculosis agents may include by way of example, but not oflimitation to, Ethambutol, Isoniazid, Pyrazinamide, Rifabutin andRifampin

Antivirals may include by way of example, but not of limitation to,Acyclovir, Amantadine, Famciclovir, Foscamet, Ganciclovir, Ribavirin,Valacyclovir and Valganciclovir.

Antiretrovirals may include by way of example, but not of limitation to,Abacavir, Amprenavir, Didanosine, Efavirenz, Indinavir, Lamivudine,Loopinavir, Nelfinavir, Nevirapine, Ritonavir, Saquinavir, Stavudine,Zalcitabine and Zidovudine.

Antimalarials may include by way of example, but not of limitation to,Chloroquine, Hydroxychloroquine, Pyrimethamine and Quinine.

Quinolones may include by way of example, but not of limitation to,Gatifloxacin, Levofloxacin and Ofloxacin.

Sulfonamides may include by way of example, but not of limitation to,Sulfadiazine, Sulfamethoxazole, Sulfasalazine and Sulfisoxazole.

Sulfones may include by way of example, but not of limitation to,Dapsone.

Urinary anti-infectives may include by way of example, but not oflimitation to, Nitrofurantoin.

Miscellaneous anti-infectives may include by way of example, but not oflimitation to, Clofazamine, Co-trimoxazole, Metronidazole andPentamidine.

Anti-adhesions agents may include by way of example, but not oflimitation to, Aspirin, Calcium channel blockers,Carboxymethylcellulose, Chondroitin sulfate, Corticosteroids, Chymaseinhibitors, Dextran, Dialysis solution, Diphenhydramine, Fibrin glue,Haparin, Hyaluronic acid, L-Arginine, Methylene blue, Mifepristone,Mitomycin C, NSAIDs, Octreotide, Pentoxifylline, Peritoneal transplant,Photopolymerized hydrogel, Polyethylene glycol, Polyoxamer, Ringerslactate, Saline, Surfactant and tissue plasminogen activator.

Also known are solutions or gels such as Hyaluronic acid,Hyalutronate-carboxymethylcellulose, Carboxymethylcellulose,Polyethylene glycol, Dextran 70 and Icodextrin 4%.

The preceding are liquids, solutions or gels which it is believed withinthe skill of those in the art to use in the present invention. Alsoknown are commercial anti-adhesion barriers such ashyaluronate-carboxymethylcellulose, oxidized regenerated cellulose,polyethylene oxide-oxidized regenerated cellulose, expandedpolytetrafluoroethylene and pericardial patch.

The use of these in the present invention may require shredding,pulverizing or powdering together with mixing them with a liquid to makethem usable in the present invention.

The present invention contemplates use of yet to be invented agents ofthe above classes, as well as any of those drugs of the above classeswhich have not been listed.

Referring to FIGS. 16-20, there are shown embodiments of the presentinvention which are thought to be particularly useful in providingagents to be delivered, along with insufflation gas, whether treated ornot, to the abdomen of a patient. There is shown an insufflation device,at least one structure defining at least one fluid flow path extendingat least a portion of the distance between the insufflation device andthe abdomen of a patient, and a chamber adapted to be coupled to the atleast one structure and adapted to supply an agent to the interior ofthe abdomen through the at least one structure.

FIG. 16 shows an apparatus comprising an insufflation device 915, whichmay be such as the Stortz Model 26012 mentioned above, or any otherinsufflation device that supplies insufflation gas to a surgical site.The insufflation device 915 has an outlet 916 through which it suppliesinsufflation gas.

There is optionally provided downstream of the insufflation device 915,and in fluid communication therewith, the heater/hydrator 120 of thepresent invention. The heater/hydrator 120 has an inlet 917 and anoutlet 918. A first conduit 919 connects the insufflation device outlet916 with the inlet 917 of the heater/hydrator 120, thus placing theinsufflation device 915 in fluid communication with the heater/hydrator120.

In any of the embodiments set forth herein, conduits may be short orlong, wide or narrow. In some cases, the conduits may be separate piecesfrom devices they are in fluid communication with, while in other casesthe conduit may be formed together with such devices. In some cases,various devices may be connected or coupled together without conduitsbetween them. In some cases, various devices may be formed as a singledevice with multiple chambers. All such embodiments are within the scopeof the invention.

The addition of an agent into the gas stream which is going into thepatient's abdomen may be beneficial whether or not the insufflation gasis dry or humidified, or warm or cold. The scope of the presentinvention covers the addition of an agent under any conditions. Thepreferred method is one in which the insufflation gas is heated andhumidified.

A second conduit 920 is connected at its first end 920A to the outlet918 of the heater/hydrator 120, and is open at its second end 920B.Either end may include one or more connectors, such as, for example, aLuer lock. During surgery, the second conduit may be connected to, orplaced in fluid communication with trocar assembly 921 which haspreviously been placed into the abdomen 922 of the patient P, thusplacing the heater/hydrator in fluid communication with the patient'sabdomen. A Veres needle or other device could also be used to provideaccess to the abdomen without departing from the scope of the presentinvention. The first conduit 919, or second conduit 920, may have afilter attached thereto.

In this embodiment of the present invention, an agent chamber 925 isprovided external and separate of the heater/hydrator 120. The agentchamber 925 has at least an outlet 926. A third conduit 927 is connectedat its first end 927A to the outlet 926 of the agent chamber. The thirdconduit 927, at its other end 927B, may be in flow communication withthe trocar assembly 921 (or could be in flow communication with conduit920 if an appropriate connector was used).

A two-inlet trocar assembly 930 (FIG. 31) may be provided. Or, ifdesired, a modified trocar 933 (FIG. 32) may be provided. Since thethird conduit is open to atmosphere, some pressure source, other thanthe insufflation device 915, is employed to drive the agent in the agentchamber 925 into the insufflation gas stream. An example pressure sourceis described below.

A dispersion device 948 may be used to promote the entry of the agentinto the abdomen 922 of the patient P as an aerosol spray, mist, fog orvapor. It is believed that the dispersion device will promote theeffectiveness of the agent.

The dispersion device placement may depend on where and how the agent isintroduced to the insufflation gas stream. It is believed that when theagent chamber 925 is not connected in line, the dispersion device may beanywhere in the third conduit 927 or in the trocar 921.

Referring now to FIG. 17, a modification of the construction shown inFIG. 16 is provided. In this embodiment, the insufflation device 915having outlet 916 is again provided. The heater/hydrator 120 has itsinlet 917 connected to the outlet 916 of insufflation device 915 by thefirst conduit 919. However, in this embodiment, the modified agentchamber 935 (referred to as modified because of having an inlet and anoutlet), having an inlet 936, and an outlet 937, is placed in-line withthe heater/hydrator 120 and connected thereto by second conduit 920.Therefore, the pressure of the insufflation gas may be used to drive theagent, if desired. The term “modified agent chamber” is used forconvenience and is not meant to create a special definition of either“agent chamber” or “modified agent chamber” in the claims. As used inthe claims, the term “agent chamber” is meant to refer broadly to anychamber that may contain an agent.

A fourth conduit 938 is connected to the outlet 937 of agent chamber935. The fourth conduit 938 may be used to place the agent chamber 935in fluid communication with the trocar assembly 921 in the abdomen 922of a patient P during a surgical procedure. The dispersion device 948may be anywhere downstream of the modified agent chamber 935, such asinterposed or connected to the fourth conduit 938. As discussed above, adevice other than a trocar 921 could be used to provide access to theabdomen, such as, for example, a Veres needle.

One skilled in the art will appreciate that, depending on the nature ofthe dispersion device 948, it may be placed in the conduits describedherein, with the fluid flowing through the dispersion device 948, oraround it, or, the dispersion device 948 could surround the conduit.Depending on the application, for any particular conduit, there may be adispersion device both, in a conduit, and external to it.

In FIG. 18, the agent chamber 925 is connected upstream of theheater/hydrator 120. It is connected in flow communication with theheater/hydrator 120 by fifth conduit 940. Fifth conduit 940 may beconnected anywhere between the outlet 916 of the insufflation device 915and the inlet 917 of the heater/hydrator 120 to place the agent chamber925 in flow communication with the heater/hydrator 120. As before,second conduit 920 is connected to the outlet 918 of the heater/hydrator120, and places the heater/hydrator 120 in fluid communication with thepatient's abdomen through trocar assembly 921. As discussed above, adevice other than a trocar 921 could be used to provide access to theabdomen, such as, for example, a Veres needle.

Since the agent chamber 925 is connected in parallel with theinsufflation device 915, the dispersion device 948 may be connected orplaced anywhere downstream of the agent chamber 925, for example, in thesecond conduit 920.

The embodiment shown in FIG. 19 is similar to that shown in FIG. 17,except that the modified agent chamber 935 having inlet 936 and outlet937 is placed upstream of the heater/hydrator 120, instead of downstreamthereof. First conduit 919 may now be connected between the outlet 916of the insufflation device 915 and the inlet 936 of the modified agentchamber, thus placing the modified agent chamber 935 in fluidcommunication with the insufflation device 915.

A sixth conduit 941 connects the outlet 937 of the modified agentchamber 935 to the inlet 917 of the heater/hydrator 120. A seventhconduit 942 is connected to the outlet 918 of the heater/hydrator 120.Seventh conduit 942 may be placed in fluid communication with a trocar921 assembly which has previously been placed in the abdomen 922 of apatient P during a surgical procedure. As discussed above, a deviceother than a trocar 921 could be used to provide access to the abdomen,such as, for example, a Veres needle. When gas is flowing from theinsufflation device 915, and there is agent remaining in the modifiedagent chamber 935, the agent may be delivered into the abdomen 922 ofthe patient P. As before, dispersion device 948 may be placed anywheredownstream of the agent chamber, such as interposed in, or connected toseventh conduit 942.

The embodiment shown in FIG. 20 is similar to the embodiment shown inFIG. 18, except that the agent chamber 925, having outlet 926 isconnected downstream of the heater/hydrator 120, instead of upstream.First conduit 919 is connected between the outlet 916 of theinsufflation device 915 and the inlet 917 of the heater/hydrator,thereby placing heater/hydrator 120 in fluid or flow communication withthe insufflation device 915.

Second conduit 920 is connected to the outlet 918 of the heater/hydrator120. As before, second conduit 920 may be placed in flow communicationwith a trocar assembly 921 that has been placed into the abdomen 922 ofa patient P during a surgical procedure. As discussed above, a deviceother than a trocar 921 could be used to provide access to the abdomen,such as, for example, a Veres needle. The outlet 926 of the agentchamber 925 has an eighth conduit 943 connected thereto. The other endof eighth conduit 943 may be connected in flow communication with thegas stream coming from the heater/hydrator anywhere between the outlet918 of the heater/hydrator 120 and the trocar assembly 921. Dispersiondevice 948 may be placed anywhere downstream of the agent chamber 925,such as being interposed in, or connected to, second conduit 920. Whenpressure is applied to the agent in the agent chamber 925, whether ornot gas is flowing from the insufflation device 915, agent may besupplied into the abdomen 922 of the patient P.

Depending on the application, the constructions shown in FIGS. 1-20 maybe combined or duplicated to achieve the desired results. For example,one or more agents may be introduced through the heater/hydrator 120,and one or more agents may be introduced through one or more agentchambers (925,935). Also, any of the chambers shown may be single ormultiple chambers, so as to provide for the addition of multiple agents.The gas may be heated and/or humidified, as desired. The chambers may beempty chambers, or have various means to absorb or adsorb liquid inthem.

Referring now to FIG. 21, there is shown one way in which agent may beintroduced into an agent chamber (925,935). Although modified agentchamber 935 is illustrated in FIG. 21, the apparatus shown will alsowork with agent chamber 925. An external port 950 is provided, which mayhave a closure member 968 to regulate flow through the port 950, intowhich syringe 951 containing the desired amount of agent may beinserted. At the proper time, the surgeon, anesthetist, or other medicalpersonnel, will open the closure member 968, if present, and depress theplunger 952 of syringe 951 to inject the agent into the agent chamber(925,935), where it will travel to the patient's abdomen in the mannerpreviously described.

Referring now to FIG. 22, there is shown another device that may serveto introduce agent into an agent chamber (925,935) in variousembodiments of the present invention. In this embodiment, pump 954 isused to deliver the agent to the agent chamber (925,935). An externalport 950 is provided to which pump 954, such as a peristaltic or othersuitable type pump, is connected. A closure member 968 may be providedto regulate the flow into the port 150. A reservoir (not shown)containing at least the desired amount of agent is provided.

At the proper time, the surgeon, anesthetist, or other medicalpersonnel, will open the closure member 968, if present, activate thepump 954 to supply the desired amount of the agent into the agentchamber (925, 935), where it will travel to the patients abdomen in themanner previously described. Note that in any of the embodimentdiscussed herein, closure member 968 could be an adjustable valve.

Referring now to FIG. 23, there is shown a still further device that mayserve to introduce agent into an agent chamber (925, 935) in embodimentsof the present invention. In this embodiment, a pressurized cylinder 956which has been pre-charged with a desired amount of agent is used todeliver the agent to the agent chamber (925, 935). An external port 950is provided to which pressurized cylinder 956 is connected. A closuremember 968 is interposed between cylinder 956 and port 950. Thepre-charged cylinder, in addition to having a desired amount of agentcontained therein, may have a predetermined amount of a pressurizingagent, such as an inert gas, contained therein, and may have apparatus(e.g. an electronically controlled valve) to cause the release of theagent at the desired time. At the proper time, the surgeon, anesthetist,or other medical personnel, may open the closure member 968, if present,and activate the release apparatus to supply the desired amount of theagent into the agent chamber, where it will travel to the patientsabdomen in the manner previously described.

Referring now to FIG. 24, there is shown yet another device which mayserve to introduce agent into an agent chamber (925, 935) of the presentinvention. In this embodiment, a flexible bag 958 containing a desiredamount of agent is connected by tubing 959 to the external port 950.Apparatus (e.g. an adjustable valve) to control the release of the agentfrom the flexible bag 958 may, or may not, be provided, depending on theapplication. The closure member 968 may serve as the release apparatus.At the desired time in the surgery, the flexible bag 958 will besqueezed, the release apparatus, if present, will be operated, and theagent will be forced into the agent chamber (925, 935).

It should be understood that all of the ways of introducing the agentinto the agent chamber (925, 935) shown in FIGS. 21-24 will work withany of the embodiments of the invention shown in FIGS. 16-20. It shouldfurther be understood that other methods of introducing agent into thechamber (925, 935) may be used without departing from the scope of theinvention.

Referring now to FIGS. 25-28, if a separate agent chamber is not desiredfor whatever reason, the syringe 951, pump 954, pressurized cylinder 956and flexible bag 958 may be used by themselves to supply agent to theembodiments of the invention shown in FIGS. 16-20. An appropriateexternal port or connector 965 may be placed in line in the appropriateconduit so that the external port or connector 965 will be in the flowpath of the insufflation gas. The operation of the various devices willbe as just described with regard to FIGS. 21-24.

Referring now to FIG. 29, there is shown an additional device that mayserve as the agent chamber (925, 935) of the present invention.Piezoelectric chamber 961 comprises a hollow chamber 962 having an inlet963 and an outlet 964. The piezoelectric chamber is connected in flowcommunication with the appropriate conduit to place it in the stream ofthe insufflation gas 970 when the insufflation device is in operation.In the hollow chamber 962 is placed a desired quantity of agent 966 inliquid form. The agent 966 will be placed in the chamber with thepiezoelectric crystal 965. Piezoelectric crystal 965 may then beenergized to activate the crystal. Activation of the crystal 965 maycause the molecules of the agent to vibrate at such speeds as to producean agent fog 967, which may be drawn into the insufflation gas stream970 and delivered to the patient's abdomen.

With reference to FIG. 30, there is shown a further alternativeembodiment of the invention which is believed useful for theadministration of agent into the abdomen of a patient. This embodimentof the invention involves the use of a modified syringe 971 being usedwith a trocar 972. The trocar 972 has a tubular portion 973 and anenlarged top portion 974. The modified syringe 971 has a normally sizedhollow body portion 978 which sealingly accepts the plunger 979 forreciprocal movement in the body portion 978. Attached to, or integralwith, the body portion 978 is an elongated, hollow, tubular, lowerportion 980 having a dispersion device 948 mounted at the distal endthereof.

In use, agent is drawn into the modified syringe assembly 971, eitherthrough a needle, or the lower tubular portion 980. If not alreadyattached, the lower tubular portion 980 is attached, and the modifiedsyringe 971 is placed into the trocar assembly 972, with the lowertubular portion 980, and the dispersion device 948, slidably fitting inthe tubular portion of the trocar 972.

The elongated tubular portion 980 of the modified syringe should be longenough so that when the modified syringe 971 is inserted in the trocar,the distal end 980A of the lower tubular portion 980 extends past theend of the tubular portion 973 of the trocar 972. In this manner, duringsurgery, when it is desired to add agent to the abdomen, and themodified syringe 971 is fully inserted into the trocar 972, thedispersion device 948 may actually be inside the pneumoperitoneum.Therefore, when the plunger 979 is depressed, the agent that haspreviously been drawn into the modified syringe 971 may be forcedthrough the dispersion device 948, and may directly enter the abdomen asan aerosol, spray, mist, fog or vapor, depending on the dispersiondevice 948 used, and the agent. Some agents may not be capable of beingdispersed in all forms.

Referring now to FIG. 31, there is shown a two-inlet trocar 930.Two-inlet trocar 930 is similar in some respects to trocars known in theart in that it has a tubular body portion 975, having an enlarged topportion 975A and has a single inlet 976 for the admission ofinsufflation gas, such as that which may be supplied from insufflationdevice 915. Due to the potential desirability of introducing the agentinto the insufflation gas stream right at the trocar, two-inlet trocar930 with second inlet 977 may be desirable. When desired, theinsufflation gas stream may enter the two-inlet trocar 930 through firstinlet 976, and the agent gas stream may enter the trocar through thesecond inlet 977 (or vice versa).

A modification of the trocar construction shown in FIG. 31 is shown inFIG. 32. Modified trocar 933 is shown. Modified trocar 933 has a tubularbody portion 975 and enlarged top portion 974 as before. In addition, ithas inlet 976. However, instead of having a second inlet 977, it has abranch inlet 934 which branches off the inlet 976 to provide for theagent stream to be connected directly to the modified trocar 933, butwithout the provision of an entirely separate second inlet. A dispersiondevice 948 is optionally provided at the distal end of the branch outlet934. Closure members 968 are optionally provided.

Referring now to FIG. 33, a further embodiment of the invention, whichis, in some respects similar to the embodiment shown in FIG. 32, isshown. This embodiment of the invention uses most of the construction ofFIG. 32 in that the modified trocar 933 having a lower tubular portion975 and enlarged top portion 974 is used with a single inlet 976 and abranch outlet 934. In this modification, the branch inlet is sized andshaped to accommodate a pressurized aerosol spray can 981 which has adesired amount of agent and propellant contained therein.

The pressurized container or spray can 981 has a nozzle 982 with anorifice that should be chosen, depending on the agent being used, tocreate an aerosol spray, mist, fog, or vapor, if possible. The nozzle982 may be adapted to be press fit onto the branch inlet 934. Becausethe nozzle may create the desired dispersion, dispersion device 948 maybe omitted in this embodiment of the invention, but could also beincluded, if desired.

Referring now to FIG. 34, there is shown a flow chart illustrating aseries of steps in which various embodiments of the invention may beused. At Box 1000, the first step is to gain access to the abdomen 922of the patient P. This may be done by any of several well known surgicaltechniques known to those skilled in the art of surgery, and willusually involve making a surgical incision in the patient's abdomen andinserting a trocar therein.

Next (Box 1010) a gas stream of insufflation gas may be introduced intothe patient's abdomen 922. This will involve the steps of providing aninsufflation device 120, creating a flow path between the insufflationdevice and the trocar, and initially inflating the patient's abdomenwith about 2-3 liters of insufflation gas. After the initial inflationof the patient's abdomen, insufflation gas may continue to flow into theabdomen at the desired rate or may cease to flow depending upon theparticular circumstances.

The agent, or agent stream may then be introduced into thepneumoperitoneum along with the insufflation gas (Box 1020). Apredetermined concentration suitable for a particular procedure may bechosen.

Once the desired concentration of agent has been determined for thesurgical procedure being performed, there are several ways the agent maybe introduced into the pneumoperitoneum, as described above.

Regardless of the method used, when the desired amount of agent has beenintroduced, the flow of agent or agent stream will be shut off (Box1030).

Throughout this application, various patents publications arereferenced. The disclosures of these publications in their entiretiesare hereby incorporated by reference into this application in order tomore fully describe the state of the art to which this inventionpertains.

Although the present process has been described with reference tospecific details of certain embodiments thereof, it is not intended thatsuch details should be regarded as limitations upon the scope of theinvention except as and to the extent that they are included in theaccompanying claims.

1. An apparatus for introducing at least one agent into the abdomen of apatient comprising: a) An insufflation device to provide pressure andvolumetrically controlled gas in a manner suitable for laparoscopicsurgery in a volume to provide full insufflation of the abdominalcavity; b) a heater/hydrator connected to the insufflation devicedownstream thereof, the heater/hydrator having a heater and an absorbentmaterial contained therein; c) at least a first structure comprising atleast a first fluid path for the pressure and volumetrically controlledgas extending at least a portion of the distance between theinsufflation device and the heater/hydrator; d) at least a secondstructure comprising at least a second flow path for the pressure andvolumetrically controlled gas extending at least a portion of thedistance between the heater/hydrator and the abdomen; and e) an agentchamber or a modified agent chamber separate and external from theheater/hydrator connected to either the first structure or the secondstructure, or both, to supply the at least one agent to the pressure andvolumetrically controlled gas while it is flowing through either thefirst flow path, or the second flow path, or both.
 2. The apparatus ofclaim 1, wherein the chamber is a syringe.
 3. The apparatus of claim 1,wherein the chamber is a bag.
 4. The apparatus of claim 1, wherein thechamber is a pump.
 5. The apparatus of claim 1, further comprising adispersion device external and separate of the heater/hydratorconfigured to cause dispersion of the agent, wherein said dispersiondevice produces an aerosol.
 6. The apparatus of claim 1, furthercomprising a dispersion device external and separate of theheater/hydrator configured to cause dispersion of the agent, whereinsaid dispersion device produces a spray.
 7. The apparatus of claim 1,further comprising a dispersion device external and separate of theheater/hydrator configured to cause dispersion of the agent, whereinsaid dispersion device produces a mist.
 8. The apparatus of claim 1,further comprising a dispersion device external and separate of theheater/hydrator configured to cause dispersion of the agent, whereinsaid dispersion device produces a fog.
 9. The apparatus of claim 1,further comprising a dispersion device external and separate of theheater/hydrator configured to cause dispersion of the agent, whereinsaid dispersion device produces a vapor.
 10. The apparatus of claim 1,wherein the chamber is a piezoelectric chamber.
 11. The apparatus ofclaim 1 further including: a) at least a third structure in fluidcommunication with either the first structure, or the second structure,or both, and comprising at least a third flow path for the pressure andvolumetrically controlled gas extending at least a portion of thedistance between the abdomen and the agent chamber or modified agentchamber ; and b) the agent chamber or modified agent chamber separateand external from the heater/hydrator connected to the third structureand adapted to supply the at least one agent to the pressure andvolumetrically controlled gas while it is flowing through the third flowpath.
 12. An agent delivery system for use with an insufflation devicecapable of providing pressure and volumetrically controlled gas in amanner suitable for laparoscopic surgery to the abdomen of a patientcomprising: a) at least a first structure comprising at least a firstfluid flow path for the pressure and volumetrically controlled gasextending at least a portion of the distance between the insufflationdevice and the abdomen; b) an agent chamber or a modified agent chamberseparate and external from a heater/hydrator connected to the at least afirst structure to supply at least one agent to the pressure andvolumetrically controlled gas while it is flowing through the at least afirst fluid flow path, wherein the agent chamber , or modified agentchamber, has an external port to accept a charging device.
 13. Anapparatus for producing a pressure and volumetrically controlled gasstream carrying an aerosol, spray, mist, fog or vapor of an agentcomprising: a) an insufflation device to provide pressure andvolumetrically controlled gas in a manner suitable for laparoscopicsurgery in a volume to provide full insufflation of an abdominal cavity; b) a heater/hydrator connected to the insufflation device downstreamthereof, the heater/hydrator having a heater and an absorbent materialcontained therein; c) at least a first structure comprising at least afirst fluid path for the pressure and volumetrically controlled gasextending at least a portion of the distance between the insufflationdevice and the heater/hydrator; d) at least a second structurecomprising at least a second flow path for the pressure andvolumetrically controlled gas extending at least a portion of thedistance between the heater/hydrator and the abdomen; and e) an agentchamber or a modified agent chamber separate and external from theheater/hydrator connected to either the first structure or the secondstructure to supply the aerosol, spray, mist, fog or vapor of an agentto the interior of the abdomen by supplying the aerosol, spray, mist,fog or vapor of an agent to the pressure and volumetrically controlledgas stream while it is flowing through either the first flow path, orthe second flow path, or both.
 14. An apparatus for introducing at leastone agent into the abdomen of a patient comprising: a) an insufflationdevice to provide pressure and volumetrically controlled gas in a mannersuitable for laparoscopic surgery in a volume to provide fullinsufflation of the abdominal cavity; b) a heater/hydrator connected tothe insufflation device downstream thereof, the heater/hydrator having aheater and an absorbent material contained therein; c) a first structurecomprising a first fluid path for the pressure and volumetricallycontrolled gas extending between the insufflation device and theheater/hydrator; d) a second structure comprising a second flow path forthe pressure and volumetrically controlled gas extending between theheater/hydrator and the abdomen; and e) an agent chamber or a modifiedagent chamber separate and external from the heater/hydrator connectedto either the first structure or the second structure to supply theagent to the interior of the abdomen through the pressure andvolumetrically controlled gas by adding the agent to the pressure andvolumetrically controlled gas while it is flowing through either thefirst flow path, or the second flow path, or both.
 15. An apparatus forintroducing at least one agent into the abdomen of a patient comprising:a) an insufflation device to provide pressure and volumetricallycontrolled gas in a manner suitable for laparoscopic surgery in a volumeto provide full insufflation of the abdominal cavity; b) aheater/hydrator connected to the insufflation device downstream thereof,the heater/hydrator having a heater and an absorbent material containedtherein; c) a first structure comprising a first fluid path for thepressure and volumetrically controlled gas extending between theinsufflation device and the heater/hydrator; d) a trocar, e) a secondstructure comprising a second flow path for the pressure andvolumetrically controlled gas extending between the heater/hydrator andthe trocar; and f) an agent chamber or a modified agent chamber separateand external from the heater/hydrator connected to either the firststructure or the second structure, to supply the at least one agent tothe pressure and volumetrically controlled gas in either the first flowpath, or the second flow path, or both.
 16. An apparatus for introducingat least one liquid agent into the abdomen of a patient comprising: a)an insufflation device to provide pressure and volumetrically controlledgas in a manner suitable for laparoscopic surgery in a volume to providefull insufflation of the abdominal cavity; b) a heater/hydratorconnected to the insufflation device downstream thereof, theheater/hydrator having a heater and an absorbent material containedtherein; c) at least a first structure comprising at least a first fluidpath for the pressure and volumetrically controlled gas extending atleast a portion of the distance between the insufflation device and theheater/hydrator; d) at least a second structure comprising at least asecond flow path for the pressure and volumetrically controlled gasextending at least a portion of the distance between the heater/hydratorand the abdomen; and e) an agent chamber or a modified agent chamberseparate and external from the heater/hydrator connected to either thefirst structure or the second structure, or both, to supply the at leastone liquid agent to the pressure and volumetrically controlled gasthrough either the first flow path, or the second flow path, or both.17. An apparatus for introducing at least one solid agent into theabdomen of a patient comprising: a) an insufflation device to providepressure and volumetrically controlled gas in a manner suitable forlaparoscopic surgery in a volume to provide full insufflation of theabdominal cavity ; b) a heater/hydrator connected to the insufflationdevice downstream thereof, the heater/hydrator having a heater and anabsorbent material contained therein; c) at least a first structurecomprising at least a first fluid path for the pressure andvolumetrically controlled gas extending at least a portion of thedistance between the insufflation device and the heater/hydrator; d) atleast a second structure comprising at least a second flow path for thepressure and volumetrically controlled gas extending at least a portionof the distance between the heater/hydrator and the abdomen; and e) anagent chamber or a modified agent chamber separate and external from theheater/hydrator connected to either the first structure or the secondstructure, or both, to supply the at least one solid agent to thepressure and volumetrically controlled gas flowing through either thefirst flow path, or the second flow path, or both.
 18. The apparatusdefined in any one of claim 1, 5, 12, 11, 13, 14, 15, 16 or 17, whereinthe agent is a chemotherapy agent.